I've got a couple of partitions on my primary hard drive that I somehow managed to mount quite some time ago. Both partitions are EXT4, and not readable by Windows. (Back when I originally mounted them, they were EXT2, and I had a driver that worked for reading/writing them). Currently they show up in my computer as E:\ and F:. I'd be content to let them stay there, useless, forever, but I will be passing this machine on to another user shortly, and attempting to open the drives results in a "Would you like to format this disk?" dialog, which is obviously dangerous. I want to dismount both drives so that they don't show up in my computer.
How they look:
The standard way of dismounting drives like this is through computer management, where one could normally just remove the drive letter. However, that option is not available:
Other things I have tried:
The "Mountvol" command helpfully suggested in this question dissapears the drives nicely, but they reappear after a reboot.
The "fsutil" command, which refuses to perform operations on non-NTFS partitions.
KCotreau suggested trying diskpart, which was able to remove the drive letters, but they reappeared on the next boot.
Please note that I do not want to delete the partitions, as they are still used by Linux.
Any suggestions are welcome.